Improvement in drawing-board attachments



UNITED STATES PATENT OFFICE.

JULIUS o. runrz, on onnron, oHIo.

IMPROVEMENT IN DRAWING-BOARD ATTACHMENTS.

Specification forming part of Letters Patent No. 169,543, dated November2, 1875; application filed August 13, 1875.

panying drawings, which form part of this specification.

My invention relates to improvement in devices for squaringdrawing-tables; and consists in border-rails of metal or other suitablematerial, which rails are made adjustable, both vertically andhorizontally, so that those upon adjacent sides can be readily broughtto an exact right angle, the said border-rails and their attachmentsbeing so constructed that they may be applied to any ordinary table.

In the drawing, Figure 1 is an inverted plan view of a table having theadjustable borderrails. Fig. 2 is a side view of same. Fig. 3 is alongitudinal vertical section through the center of one of theadjustable supports.

A may be any ordinary table the edges of which have never beensquaredniathematically. The object of this invention is to form anattachment which may be readily secured to this table, whereby it can bemade perfectly square, and the edges rendered perfectly straight, so asto be in proper condition for use as a drawing-table. This is effectedas follows: B are metallic or other strips, the outer edges of which aremade perfectly straight and true. Each of these edges B is supported bytwo adjustable supports, to be applied underneath, as shown in thedrawings. One of these supports is represented in section in Fig. 3. Ois a bed-plate, which is securely screwed or otherwise fastened to theunder side of the table at its edge. D is a shaft, passing through thesupports 0 of the bed-plate G, in which supports it slides bearingagainst the shoulder 0 so. that, by turning the mill-head so as to run.out. the screw E, the point will bear against the shoulder G andconsequently drive the shaft D slowly outward in the opposite,direction. F is a screw cut shaft, which slides freely up anddo'wnthrough a collar, D in theend of the shaft D. This screw-cut shaftF has two milled nuts, G, upon it, one above and one below the collar DAt the upper end ofthe screw-cut shaft F is a clutch or jaw, H, and aset-screw, El, This. jaw receives the projecting rib or lug b, whichprojects downward from the metallic edge B, and may there be rigidlysecured by' the set-screw H. There are two of these supports for each ofthe metallic edges B. Y

The operation of the device is as follows: The supports having beenattached to the under side of the table A, the edges B are properlyadjusted in the clutches H. Now, if either end of the strip B is notexactly onthe level of the table it can be raised or lowered, so as tobe brought into that level, by the following operation: If, forinstance, it is necessary to raise one of its ends, the operator loosensthe-milled nut Gr that is beneath the collar D then, by turning in thesame direction the nut G that is above the collar, the metallic edge Bis gradually lifted up until it is in the plane of the table; the lowernut G- is then tightened up. If it is necessary, in order to make thetable square, that either end of one of the edges B shall be carriedfrom the table, it is effected as followsz The operator loosens theset-screw D he then turns the milled headed screw E in a direction torun out the screw; its point, impinging against the shoulder 0 willdrive the shaft D gradually in the opposite direction, which, in turn,will carry its end of the metallic edge B with it. In this way themetallic edges B can both be brought into the plane of the table, and beadjusted so as to be at exact right angles with each other.

In order that the shaft D maynot roll upon its axis the set screw D ismade to enter a groove, d, in the under side of the shaft D.

The edges B may be formed of any suitable material. It may be in theshape of 'an angle 2 I d I 169,543

iron, or in the shape of T-iron in cross-section, or of any suitableshape, whereby there are projections beneath to enter the jaws H.

The drawings represent the edges as arranged only upon two adjacentsides of the table; but it is evident that they may, if -desired, bearranged upon all sides.

It will be observed that the metallic edges B, as well as the shafts D,are readily removable from the bed-plates (3. Thus, where a draftsman isworking upon several tables, if

the bed-plates O are placed upon each of the tables he can readilyshiftthe edges B and the shafts D from one table to another.

It is also evident that the invention is not limited to the particularmeans employed for givingeither the horizontal or vertical adjustment.Those adjustments may be effected in various manners; but'the methodsshown in I the drawing are very'simple and effective.

, In order that the edges Bmay not be accident-all y disarranged orlifted from the clutches H, I provide a set-screw, H, which, by bearingupon the'projection b, will prevent any such accident, which wouldotherwise readily occur while either working around the table, or by aperson brushing against it in passing.

' Havingfullydescribedmyinvention, what I claim as new, and desire tosecure by Letters Patent, is

1. A squaring attachment for drawing-tables, consisting of theborder-rails B, in combination with horizontal and vertical adjustingmechanism, substantially as and for the purpose described.

2. The combination, with a table, of bedplate 0, having shoulders (J andsupport 0 substantially as and for the purpose described.

3. The border-rails Band jaws H, provided with shaft F and milled nutsG, whereby the clutch can be adjusted up or down, in combination with ashaft or support, D, and screw 7 E, and the shaft can be adjustedhorizontally, substantially as and for the purpose described.

4; The combination, with the table A, of bed-plate O, shaft D, screw E,shaft F, nuts G, and jaws H, substantially as and for the purposedescribed.

5. The. combination, with the border-rails B and rib'b, of jaw H andset-screw H, substantially as and for the purpose described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JULIUS G. HINTZ.

Witnesses:

W. WALLACE DUNCAN, LOUIs SOHAEFER.

